GPS, Google Maps, and CourseKey location technologies
CourseKey’s proprietary attendance-location technology is used in combination with industry-standard Google Maps and government-provided GPS technology which have important limitations on their accuracy. You can use this article to better understand this technology and make optimal decisions to tune, restrict or broaden the allowable area for attendance check-ins to account for these limitations and avoid unnecessary failures and burdens on staff or students.
GPS uses satellites to provide users (including our own Federal Aviation Administration) with “approximately 7.0 meter accuracy, 95% of the time”. Per the official US government GPS site, observed performance is often better, but it is not 100% guaranteed even at 7.0 meter accuracy – hence CourseKey does not generally recommend setting a check-in radius below this level.
To set pinpoint locations that are acceptable centerpoints (or latitude/longitude-denominated ‘geocodes’) for an allowable radius for a student’s location to do a check-in or check-out, we use Google Maps. CourseKey simply relies on the map SDK provided by Google to do address lookup and pinning location with no custom logic applied. We allow Admin users to then reposition the centerpoint to their liking on Google’s map if the requested address’s default pin from Google is not accurate to students’ expected location. (GPS.gov offers guidance on updating the location of an address for all Maps providers for troublesome locations, but this is optional and unrelated to setting pins for CourseKey sites).
GPS and Google Maps are in turn used in combination with other methods that are built-in to the mobile devices students check-in with, such as Apple Maps, cell-phone tower triangulation and wifi-hotspot mapping, all of which CourseKey cannot control. These methods usually improve accuracy beyond GPS capabilities and Google Maps data but can at times detract from it. When students report frequent failures to check-in properly when actually in their proper locations, consider a larger check-in radius and whether the pin location might be moved to allow for these errors, as well as adding other attendance technologies to GPS to verify when the radius becomes large enough to potentially be overly inclusive (of a nearby bar or coffee-shop, for example).